Tube shield



w. 5. AUGUST 3,047,649

TUBE SHIELD Filed Sept. 3, 1957 x aw INVENTOR. WILLIAM 3. AUGUST K A g-ottjr Stats see 3,647,649 TUBE SHIELD William S. August, Altadena, Caliizl, assignor to The Birtcher Corporation, Los Angeles, Caiifi, a corporation of California Filed Sept. 3, 1957, @er. No. 681,771

4 Claims. (Cl. 174-35) This invention relates to shielding devices for electron tubes and more particularly to a detachable mounting means for such a device which supports the body of the tube, conducts heat generated during the operation of the tube into the surrounding atmosphere and shields the electron tube from possible electrical interference produced by additional tubes in close proximity.

In the electronics field, as well as in others, it has been the conventional practice to employ a tube shield or cap of tubular construction adaptable to be placed over the body of a conventional electron tube and retained on said body by means of a press-fit between the shield and the body. Generally, a conventional tube shield is supported solely by the body of the tube carried in a fixed socket and there fore the tube shield is customarily forcibly pressed over the tube body and forcibly pulled from the body toseparate the shield from the tube for tube replacement.

Difiiculties are encountered when employing electron tube shields in accordance with the conventional practice which stem largely from the fact that the tube shield must be forcibly pressed over the body of the tube which places undue stress and strain on the prongs projecting from the end of the tube into a mounting socket and which sometimes breaks the body of the tube since the body usually is constructed of brittle material, such as glass. Furthermore, a conventional tube shield does not serve to support the tube within the socket, but to the contrary, relies upon the body of the tube for sole support. Because conventional tube shields are generally of a continuous cylindrical shape, a plurality of shields are required in order to be used on various diameter tube bodies.

These difliculties are overcome in accordance with the present invention wherein a novel electron tube shield is employed for dissipating heat generated during the operation of the tube into the surrounding atmosphere, which serves as a supporting means for the tube body mounted in a tube socket and protects the tube from electrical interference. The device of the present invention provides means for detachably securing the tube shield to supporting structure so that stress and strain is not placed on the body of the tube and further provides means for gripping the tube so as to offer support to the tube body in addition to the tube socket. The latter means is expandable to accommodate tubes of various diameters without necessi tating the need for a plurality of tube shields adapted for each diameter tube. The tube shield is particularly adapted for difiicult installation, such as where a tube is mounted in a socket carried by a chassis of an instrument subjected to extreme loading conditions.

Therefore, it is an object of the present invention to provide a novel electron tube shielding means which grips the body of the tube mounted in the socket and supports the body of the tube by adjacent structure whereby the shielding means relieves the prongs projecting from one end of the tube into its mounting socket from undue stress and strain under extreme loading conditions.

It is another object of the present invention to provide a novel tube shielding means which is expandable in order to accommodate tubes of varying diameters without damaging the tube or placing undue stress on the tube body.

It is another object of the present invention to provide means within a novel shielding device for an electronic 2 tube which urges the tube into constant communication with its mounting socket and actively resists efforts to remove the tube from its socket while the shield is attached.

Still a further object of the present invention is to provide a novel attachment means for securing a tube shield to adjacent supporting structure so that the tube is placed under spring tension urging the tube into its socket without disengaging the shielding means from the body of the tube.

Still a further object of the present invention is to provide means for retaining the shielding means within the mounting on a structure adjacent the tube so that the shielding means will not inadvertently disengage from its mounting.

These objects, as well as others, will be more readily apparent from -a reading of the following specification when taken in connection with the accompanying drawings wherein:

FIGURE 1 is a side elevational view of an electron tube mounted in a socket and enclosed within a shield in accordance with the present invention;

FIGURE 2 is a top view of the tube and shield of FIGURE 1 taken in the direction of arrows 2-2 showing the shield mounting means;

IGURE 3 is a sectional view of the tube and shield of FIGURE 1 taken in the direction of arrows 3-3 of FIGURE 2;

FIGURE 4 is an enlarged sectional view of the tube shielding mounting means as shown in FIGURE 3;

FIGURE 5 is a sectional view of another embodiment of the shielding means of the present invention taken in the direction of arrows 5-5 of FIGURE 6; and

FIGURE 6 is a top view of the embodiment shown in FIGURE 5.

With reference to FIGURES l, 2, and 3, a tube 9 is shown having a plurality of prongs, such as prong 10, extending from one end of a tube body 11 into selected openings (not shown) provided in a socket 12 having a plurality of electrical contacts 13 communicating therewith. Generally, contacts 13 are included in the electrical circuitry which is suitably arranged to allow elements enclosed within the tube 9 to perform their respective functions. Tube 9 may be of a conventional miniature or sub-miniature type having body 11 composed of glass, for example.

Socket 12 is provided with an integrally formed annular ridge 15 of greater diameter than socket 1i and of greater diameter than an opening 16 provided in a support 17 through which socket 12 is inserted so that contacts 13 extend therethrough. Socket 12 is secured to the support 17 by means of a plate having an opening 20 concentrically centered with opening 16 for receiving socket 12. Plate 18 is secured to the structure 17 by screws 21 whereby annular ridge 15 resides between structure 17 and plate 18.

A second structure or support 25 is provided, in addition to support 17, having an opening 26 of suitable diameter to pass the body 11 of electron tube 9. Structures 25 and 17 are supported on a chassis 9 by means of fasteners 27. Structure 25 serves to support the tube shielding means in accordance with features of the present invention. The tube shielding means comprises, in general, a substantially circular member 30 split along its full length to define a space 31 between opposing edges 32 and 33 of the member. Preferably, member 39 is composed of a resilient material so that the opposing edges may be sprung apart to increase the inner diameter of the member for accommodating various sizes of tube bodies. Also, member 30 is constructed of material, such as silver alloy or beryllium copper, having good heat conducting characteristics.

Member 30 is provided with a plurality of spaced lugs 34 integrally formed in one end of the member and the lugs are bent inwardly toward the central axis or the member to engage and retain a coil spring 35, extending from one end of member 30 toward its center. The lugs are arranged so that selected lugs engage one side of the first coil of the spring while other lugs are bent to engage the opposite side of the same coil; thereby the spring is held in place at all times. Upon installation, the spring engages the top of the tube body and is compressed against the bent lugs. The coils of the spring are of progressively smaller diameter so that the last coil engages the top of the tube body substantially about the central axis thereof. As the member 30 is slid over the body, the expansive spring action of the compressed spring urges the tube into firm engagement with socket 12.

Shield member 30 is provided with a pair of L-shaped elements 36 and 37 which are fabricated of heat conducting material and are secured on opposite sides of the member by suitable means, such as spot welding. Element 36 is secured to member 30 only adjacent edge 32 and extends over space 31 so that edge 33 may be movable relative to element 36 to permit shield member 30 to receive tubes of varying diameters.

Elements 36 and 37 are provided with flanges 39 and 38, respectively, extending radially from'the central longi tudinal axis of member 30. These flanges are employed in combination with a shield mounting means for detachably connecting the shielding member to structure 25. The mounting means comprises, in general, a spacer disc 29 engagable with the surface of member and a plate 40 carried thereon. The spacer disc is provided with a circular opening 41 which is concentric with respect to an enlarged opening 49 provided on the plate 40. The tube 9 and member pass through these openings. The opening 49 of plate is of greater diameter than opening 26 and is provided with a pair of opposing raised portions 42 and 43 projecting inwardly but not overlapping opening 41. The raised portions are separated by opposing spaces 44 and 45 which are defined by the upper surface of spacer disc 29, the thickness of plate 40 and the opposing sides of raised portions 42 and 43. Raised portions 42 and 43 are of sufficient distance from the surface of spacer disc 29 to allow the flanges of elements 36 and 37 to pass therebetween. Spaces 44 and 45 are of sufficient length and width to receive the flanges of elements 36 and 37 when the flanges engage the surface of spacer disc 29 in a flush relationship whereby the shielding means may be rotated to slip the flanges between the spacer disc 29 and raised portions 42 and 43. Spacer disc 29 is provided with flat surfaces on its opposite sides so that any irregularities present on the surface of structure 25 will not interfere with the rotation of the flanges.

Each flange and raised portion is provided with a dimple 48 such as shown in FIGURE 4, which mate with each other upon the shield means being properly centered within the aperture or opening 41. Plate 40 is suitably secured to the spacer disc 29 and to the surface of structure 25 by means of fasteners 50. The edges of raised portions 42 and 43 adjacent spaces 44 and 45 can be curved outwardly to facilitate the insertion of the elements below the raised portions.

When the shielding means is installed, the expansion action of spring 35 causes a positive metal to metal contact between the raised portions 42 and 43 of plate 40 and flanges 38 and 39. This positive contact serves as a highly satisfactory means for transferring heat generated in member 30 to the supporting structure 25. Thereby, heat may be conveniently dissipated into the structure and the surrounding atmosphere.

With reference to FIGURES 5 and 6, another embodiment of the present invention is shown whereby the elements 36 and 37 are secured adjacent one end of member 30 in order to detachably connect the shield member with the shield mounting means carried by supporting plate 18. In this embodiment, the plate 18 is positioned adjacent support 17 and is secured to support 17 by screws 21 which retain tube socket 12 within opening 16. The character references in these figures correspond to the reference characters employed to designate like structure in FIGURES 1-3.

Actual operation will be described with reference to the embodiment shown in FIGURES 13 wherein tube 9 is passed through opening 41 in plate 40 carried on structure 25 and through opening 26 provided in structure 25 so that prongs 10 may be press-fitted into openings (not shown) within socket 12, carried on supporting structure 17. When the tube has been suitably secured to socket 12, shield member 30 may be slid over body 11 of tube 9 so that spring 35 engages the top of the tube body and is compressed against the bent lugs 34 carried on member 30. Member 30 may automatically expand to spread gap 31 in order to accommodate the diameter of tube body 11. As the sliding of the shielding means proceeds over body 11 of tube 9, the flanges 38 and 39 of elements 36 and 37 are received in the spaces 44 and 45 respectively and into engagement with the surface of spacer disc 29. The member may now be rotated in either a clockwise or counterclockwise direction so that flanges associated with elements 36 and 37 are interposed between the surface of spacer disc 29 and raised portions 42 and 43 respectively. Rotation of member 30 may cease when the dimples 48 associated with the raised portion 42 and flanges 39 mate. Therefore, it is seen that the tube shielding means actively urges tube 9 into engagement with its socket by means of spring 30 and supports the body of the tube on the structure 25 (or structure 18 in the embodiment of FIGURE 5) by means of the shield mounting means.

The present invention provides a mounting means for a tube shield which is adaptable to various tube supporting structures since the position of elements 36 and 37 along the shield member 30 can be varied to accommodate any particular tube supporting structure. Also, any number of elements can be connected with the shield member for connection to more than one support. Because of the good heat conducting characteristics of' the shield member 30 and mounting elements, heat is rapidly dissipated from the tube by radiation from the shield member and by conduction to the supporting structure. Various other modifications are contempleted by those skilled in the art Without departing from the spirit and scope of the invention, as hereinafter defined by the appended claims.

What is claimed is:

1. A tube shield and attachment therefor for a tube installed in a socket comprising a split flexible shield member placed around the body of said tube and in gripping engagement therewith, with its inner surface in substantially complete contact with the outer surface of said body, support means spaced from the tube socket and having an opening for receiving the tube body and said member without contact of the member with said support means, and attachment means for detachably connecting said member to said support means, said attachment means comprising elements extending outwardly from said member and means connected with said support means and having raised portions located adjacent said opening to overlap said extending elements upon rotation of said shield member and indexing means on said raised portions and said extending elements and engageable in response to said rotation of said shield member to index said extending elements substantially centrally of said raised portions.

2. A tube shield and attachment therefor as defined in claim 1 having a plurality of lugs bent inwardly at one end of said shield member, and spring means secured to said member by said lugs and engageable with the end of said tube body to place a force thereon in the direction of the tube socket after attachment of said member to said support means and for biasing said indexing means into coactive engagement after attachment of said member to said support means.

3. A tube shield and attachment therefor comprising an elongated resilient split member slidably engageable with the tube for gripping thereof and having a pair of flanges extending radially outwardly each said flange having a dimple substantially centrally thereof, a support means carrying the socket for said tube, a mounting structure positioned in spaced relationship with said sup port means and having an opening concentric with the tube and socket, a sheet metal receptacle secured to said mounting structure about the opening, the receptacle having a pair of opposing flexible raised portions around the opening and each having a dimple complementary to said flange dimples and arranged in spaced relationship with said mounting structure to tightly receive said pair of flanges between said portions and said mounting structure whereby the tube is supported on said mounting structure by said split member and said dimples of said flanges and said raised portions are engaged to index the flanges substantially centrally of said raised portions.

4. A tube shield and attachment therefor, comprising:

a flexible shield member having a longitudinal split separating adjacent longitudinal edges thereof positionable around the body of the tube and in gripping engagement therewith, with its inner surface in substantially complete contact with the outer surface of the body:

support means for the tube;

attachment means for detachably connecting said shield member to said support means, said attachment means including means extending from said shield member and overlapping said split of said shield member;

receiving means carried by said support means for receiving said extending means, said receiving means including portions spaced from said support means so that said extending means will underlie said spaced portions upon rotation of said shield member for retaining said retaining means on said support means;

indexing means for centering said extending means relative to said portions; and

spring means carried by one end of said shield member for engaging the end of the tube body and placing a compressive force thereon after attachment of said member to said support means and for biasing said indexing means into engagement.

References Cited in the file of this patent UNITED STATES PATENTS 1,860,178 Gunther May 24, 1932 2,140,441 Clark Dec. 13, 1938 2,358,491 Del Camp Sept. 19, 1944 2,458,365 Fyler Jan. 4, 1949 2,499,612 Staver Mar. 7, 1950 2,525,769 Bruns Oct. 17, 1950 2,735,636 Snyder Feb. 21, 1956 2,773,928 Del Camp Dec. 11, 1956 2,807,659 Woods Sept. 24, 1957 2,816,948 Twig'g Dec. 17, 1957 2,825,749 Gray Mar. 4, 1958 2,872,502 Ross Feb. 3, 1959 2,899,670 Woods Aug. 11, 1959 2,908,742 Murphy Oct. 13, 1959 FOREIGN PATENTS 511,033 Germany Oct. 25, 1930 615,957 Great Britain Jan. 13, 1949 OTHER REFERENCES Publication 1: Radio Electronic Master, published by United Catalog Publishers Inc., New York, N.Y., 20th edition. Copyright 1955, Item No. 1727B, page 131U. 

